U.S. Secretary of State and National Security Adviser Marco Rubio explained in an interview with radio host Sid Rosenberg that the process involves assessing each branch individually, gathering documentation, and ensuring the designation can withstand legal challenges.

Rubio noted that any group could contest such a designation in court, and federal judges might issue nationwide injunctions, so the administration must proceed cautiously. 

He added that the U.S. is currently reviewing multiple groups for possible classification as terrorist supporters or terrorists, with the Muslim Brotherhood being of particular concern.